3 Zone Switching Relay Zoom

3 Zone Switching Relay

SKU:SR503-2

Brand: Taco

Taco
SR503-2 has been discontinued.
Direct Replacement:
SKU: SR503-4
Brand: Taco
0

Resources

Specs

Zones:
?
3
Width (Inches): 10-1/4"
Height (Inches): 6.75
Depth (Inches): 2-3/4"

Description for Taco SR503-2


Taco Switching Relays combine clearly-labeled PC board layouts with advanced features that allow you to completely customize your system. And whether you're using basic priority switching, Taco Plug-In PowerPort Cards or add-on power controls, tailoring the system has never been easier. External indicator lights give you instant diagnostic feedback, making service calls or new installation start-ups a snap. All switching relays are UL listed, use standard "ice cube" replaceable relays and are compatible with conventional and programmable thermostats. For larger jobs, switching relays can be expanded up to 20 zones with priority. With the exclusive Taco PowerPort Plug-In Cards, you can easily add such features as post purge, priority protection and pump exercise. Any expandable switching relay can also interface with the Boiler Reset Control and Injection Mixing Add-On Power Controls. Mix-and-match as needed to customize the system.
Features include:
External Indicator Lights
Switchable Priority
Simplified Wiring
Fully Enclosed Snap-Out Relays
Compact Design
Fuse Protected
100% Factory Tested
Isolated End Switch
Contractor Friendly PC Board Layout
Universal Thermostat Compatibility
UL and CSA Approved
24 Volt Power Input or Output Terminal
Extended 3 Year Warranty
Made in the USA

3 Zone Switching Relay

REVIEW SNAPSHOT®

by PowerReviews
Taco4 Zone Switching Relay
 
4.9

(based on 89 reviews)

Ratings Distribution

  • 5 Stars

     

    (76)

  • 4 Stars

     

    (13)

  • 3 Stars

     

    (0)

  • 2 Stars

     

    (0)

  • 1 Stars

     

    (0)

100%

of respondents would recommend this to a friend.

Reviewed by 89 customers

Displaying reviews 1-10

Back to top

Previous | Next »

(3 of 4 customers found this review helpful)

 
5.0

Zones!

By Matt

from Warwick RI

Verified Buyer

Comments about 4 Zone Switching Relay:

Bumping my system from three zones to ten, this controller was the perfect choice for the master position. Wiring is basic & easy, Controls the furnace & four Taco 007-f5 circulator pumps, and (in my system anyway) two Taco 503 relays.

(10 of 12 customers found this review helpful)

 
5.0

box works great

By andy

from berlin NH

Verified Buyer

Comments about 1 Zone Switching Relay:

I ordered this box, it came quick and works to perfection.

(12 of 14 customers found this review helpful)

 
5.0

Save yourself time & money.

By Meemec

from Westchester ny

Verified Buyer

Comments about 6 Zone Switching Relay:

After 37 years in the heating profession, wiring relay after relay after relay is finished!! You run one power line in, loop to each circulator, hook up thermostats and boiler TT all in one place! Saves you time, money & your back. I use this on every multi zone system.

 
5.0

Performs flawlessly

By Eric Y

from Salem, Oregon

Verified Buyer

Comments about 1 Zone Switching Relay:

Supporting installation documentation is clear and concise making it's use within reach of the average homeowner/DYI'er.

 
5.0

Easy And Simple To Use

By Clayton

from East Lyme, CT

Verified Buyer

Comments about 4 Zone Switching Relay:

I'm a home owner with some electrical experience and I was able to wiring and setup this control quickly and easily in my house. It great to be able to see which zones are calling for heat.

 
5.0

Many newer boiler may need this control

By Geo Jeff

from Ohio

Verified Buyer

Comments about 1 Zone Switching Relay:

Many newer condensing boilers that are using the downflow firetube stainless steel boiler designs now have a microprocessor control system that imposes a 4.8 DC voltage signal across the T-T terminals. Older systems that use a 24 volt signal could previously be used to operate two wire digital power stealing thermostats. With the new design boiler control this is not possible and the new boilers must be connected to either a dry contact thermostat for their T-T signal to fire or if using an electronic thermostat that must be powered, this TACO Pump control is essential as it will provide the 24 volt source necessary to operate newer digital thermostats and will also provide the dry contact relay closure for the boiler T-T signal that will now switch the 4.8 Volt DC voltage for the controls microprocessor to begin firing the boiler and operate its selected pumps via the boiler controls.

 
5.0

Easy install

By Surfer Boy

from Conifer CO

Verified Buyer

Comments about 6 Zone Switching Relay:

Great relay with easy install. SupplyHouse.com was great to work with. I ordered the wrong model by mistake and they quickly got me the correct one and full credit on the return all at the lowest price. Will definitely use them again.

 
5.0

Great product

By Rob

from Waterford NY

Verified Buyer

Comments about 4 Zone Switching Relay:

Using this switch to zone with four Circulators easy wiring setup

 
5.0

just what the doctor ordered

By rocketman

from detroit lakes, mn

Verified Buyer

Comments about 1 Zone Switching Relay:

I am not a pro, but felt like one after I installed this unit. It was the finishing touch to my infloor heating upgrade. thanks supply house, especially when they wouldnt sell it to me locally "because I didnt have a license".

 
5.0

SR 501

By Mike

from Concord MA

Verified Buyer

Comments about 1 Zone Switching Relay:

Makes adding a wi-fi therm to your customers homes easy and strait forward. Allows use of the lower priced therms that requires a "C" terminal. After all not all can afford a Nest

Displaying reviews 1-10

Back to top

Previous | Next »

Q&A: Ask the Questions, share answers

Do you have questions about this product?

Get answers from real customers and in-house experts with AnswerBox.

52 Questions | 111 Answers
Displaying questions 1-10Previous | Next »
  • 4 Zone Switching Relay

    Q:

    how to wire 4 zone switching relay to a zone valve
    Asked on 12/7/2015 by Dan from Bellefonte pa,

    1 answer

    • CUSTOMER CARE

      A:

      The SR panels are meant to control 120VAC circ. pumps not zone valves, the ZVC panel is for valves.

      Answered on 12/8/2015 by Supplyhouse Staff from New York
  • 1 Zone Switching Relay

    Q:

    can two of these units be linked together to run two zones?
    Asked on 11/13/2015 by Dan from Anchorage, AK

    1 answer

    • CUSTOMER CARE

      A:

      Yes, there is also SR502-4 that will work for two zones.

      Answered on 3/23/2016 by SupplyHouse Staff from New York
  • 4 Zone Switching Relay

    Q:

    Am I correct in understanding the use of a multi-zone switching relay will eliminate the existing Honeywell relays, by permitting direct control of the circulators?
    Asked on 1/11/2015 by skip from Burlington county, New Jersey

    3 answers

    • CUSTOMER CARE

      A:

      yes it will

      Answered on 1/12/2015 by Supplyhouse Staff from New York
    • VERIFIED BUYER

      A:

      That is the way we set it up. We replaced the old relays with this Taco
      unit.

      Answered on 1/11/2015 by Anonymous
    • VERIFIED BUYER

      A:

      The Taco multi zone switching relay controls the circulators. It does not
      replace the Aquastat relay that ignites the boiler.

      Answered on 1/12/2015 by Anonymous
  • 2 Zone Switching Relay

    Q:

    power light is green and both zone lights are red. Is this correct?
    Asked on 12/14/2014 by Dave from Barre, VT

    9 answers

    • VERIFIED BUYER

      A:

      Yes, the power led light is green and the 2 zone led lights are red.
      Paul rothstein

      Answered on 12/15/2014 by Anonymous
    • VERIFIED BUYER

      A:

      Power light is always on. Zone light are only red when the zone is calling for heat.

      Answered on 12/15/2014 by Anonymous
    • VERIFIED BUYER

      A:

      As long as both zones are calling, this is correct

      Answered on 12/15/2014 by Anonymous
    • VERIFIED BUYER

      A:

      If both lights are red it means those zones are calling for heat
      Kristian Wolff
      Wolffsystems
      "I will always go left,
      when everybody else
      goes right"

      Answered on 12/14/2014 by Anonymous
    • VERIFIED BUYER

      A:

      The green power light should always be on. The red zone lights should come
      on and off as your thermostats call for heat - on indicates the call for
      heat from that zone.

      Answered on 12/14/2014 by DonS from Oakland, CA
    • VERIFIED BUYER

      A:

      Yes
      Sent from my Virgin Mobile phone.

      Answered on 12/14/2014 by Anonymous
    • VERIFIED BUYER

      A:

      Yes, that's correct.

      Answered on 12/14/2014 by Anonymous
    • VERIFIED BUYER

      A:

      Power light is green and zone lights are red only when circulators are on.
      This is how it should be. As each zone calls for heat the light turns red
      when the circulator turns on. I hope this helps you

      Answered on 12/14/2014 by Anonymous
    • VERIFIED BUYER

      A:

      Correct

      Answered on 12/14/2014 by Anonymous
  • 2 Zone Switching Relay

    Q:

    What do you do when one zone 1 pump does not turn on even when thermostat is calling
    Asked on 11/10/2014 by tech wanna b from CT

    3 answers

    • VERIFIED BUYER

      A:

      check your installation and settings on the unit.
      If all is okay, replace the unit.
      Mike

      Answered on 11/11/2014 by Anonymous
    • VERIFIED BUYER

      A:

      I'm pretty sure that control panel had led lights to show if pumps are turned in. Is tge corresponding light lit? If so is the 120 volts on pump terminals? If no led try to short out inputs where thermostat is connected if there's voltage on pump terminals you may have bad pump
      Kristian Wolff
      Wolffsystems
      "I will always go left,
      when everybody else
      goes right"

      Answered on 11/10/2014 by Anonymous
    • VERIFIED BUYER

      A:

      #1 Check the thermostat wire at the switching relay to make sure that the circuit is closed when the tstat is calling. (broken or disconnected tstat wire) #2 Check for 110v at output to pump at switching relay. (bad relay{little plastic cube}) #3 If you have 110v to pump the pump is bad

      Answered on 11/11/2014 by Anonymous
  • 6 Zone Switching Relay

    Q:

    I have this installed with one zone set for my radiant floor. Mercury thermostat and taco zone valve that zone. Can I add an high limit aquastat (Honeywell 6006) to that zone and wire it (low voltage) to turn on the taco zone valve even if the thermostat isnt calling?

    Essentially I am creating a high heat limit dump zone for my wood boiler. If the pipe temp reaches 180 degrees, the zone will open and flow to the radiant heat. Thanks for the help.
    Asked on 10/19/2014 by Scott from Boston, MA

    2 answers

    • VERIFIED BUYER

      A:

      Yes, I wonder though if your radiant has enough btu transfer for a dump zone. The mixing valve will greatly reduce the amount of hot water drawn off the boiler. I also found on my wood boiler that using digital aquastats ( I used Johnson Controls A -419) made the switching far more consistent. The mechanical aquastats vary a lot when switching. Mine control forced air blowers and the dump zone. The mechanical ones seem to vary as much as 6 or 7 degrees and are subject to sticking(?) I noticed this because they were frequently switching when I slammed the door or tapped on the aquastat. With the digital ones if you set them to switch at say 181 degrees it will switch at 181 degrees. The price has dropped since I bought mine also. About $65.00. Good Luck, Dan

      Answered on 10/20/2014 by Anonymous
    • VERIFIED BUYER

      A:

      Absolutely. The thermostat is normally open, and the SPDT on the 6006 can
      be wired that way. So, you can wire the single zone in parallel through
      both devices. To do this you would want (ideally) to source the 24VAC from
      a single source (the SR 506 or the thermostat).
      If you have to use separate 24VAC sources for each device I would recommend
      using two zones; one for the thermostat and one for the aquastat, then wire
      the zone valve in parallel to each zone (assuming you have spare zones).
      One caveat, many safety devices would normally be wired through the normally
      closed contacts so that a wire break looks like a safety event. Not really
      a good way to do that with the 506, you would need an interposing relay and
      that defeats the purpose.

      Answered on 10/20/2014 by DonS from Oakland, CA
  • 6 Zone Switching Relay

    Q:

    which relay is priority for my indirect hot water tank ? sr506-4 . thanks, gary
    Asked on 6/9/2014 by gary

    2 answers

    • VERIFIED BUYER

      A:

      Zone 6. See here
      <http://s3.supplyhouse.com/manuals/13***.****6/85287_PROD_FILE.pdfc> .

      Answered on 6/9/2014 by DonS from Oakland, CA
    • VERIFIED BUYER

      A:

      the last zone, in your case zone 6 is the priority but there is a switch you must turn on so the priority is active top right side of circuit board

      Answered on 6/9/2014 by Anonymous
  • 6 Zone Switching Relay

    Q:

    Does this switching relay have a "primary" pump control? Im thinking of using a Primary/Secondary type system and I will need the Primary pump to start when ever one of the zones calls for heat.
    Asked on 4/14/2014 by Eric

    7 answers

    • VERIFIED BUYER

      A:

      NO
      Sent from my iPad

      Answered on 4/15/2014 by Bob from Long Island
    • VERIFIED BUYER

      A:

      It will turn make the booker call for heat so just wire the primary circulator off of the boiler. Once a Tstat calls fir heat the secondary pump will start, once boiler starts then the primary pump will as well
      Kristian Wolff
      Wolffsystems

      Answered on 4/14/2014 by Anonymous
    • VERIFIED BUYER

      A:

      Sort of.
      Whenever any of the zones calls for heat the boiler start signal at X-X will
      be closed. This signal is intended to start the boiler, if you're not using
      it for boiler control you can use it to start a primary pump. The X-X
      signal is a control signal, it is not rated for full power to the pump like
      the zone relay outputs. If you don't need all 6 zones then you can use one
      of the zone relays for your primary. Connect the X-X contacts to the
      thermostat input for the zone you want to use for your primary. Then,
      whenever any zone calls for heat X-X will close, which in turn will be seen
      as a call for heat on the primary zone. When the other zones clear the X-X
      will open (the circuit doesn't seal itself), causing the primary to shut
      down.
      If you don't have a spare zone you can do the same thing with an external
      primary pump relay (the SR501 or pretty much any other suitable relay).
      If you also want to use the X-X signal for the boiler then it gets more
      complicated.

      Answered on 4/14/2014 by DonS from Oakland, CA
    • VERIFIED BUYER

      A:

      I am not sure it needs to have a primary pump relay. In a normal
      single-pump set-up, the thermostat gets wired into the boiler's control
      panel. When the thermostat calls for heat, the boiler closes the loop for
      the system pump, and water flows through the entire heating system.
      The way I set-up my system, I had three zone pumps on the secondary loop
      and a small circulator on the primary (boiler) side. The three zone pumps
      were wired into the switching relay, along with the respective zone
      thermostats. When a thermostat called for heat, it would signal the
      switching relay which does two things. 1) it closes the loop to the
      corresponding zone pump(s) and 2) it signals the boiler there is a call for
      heat, using the same wiring connection as the thermostat in a single zone
      system. So now when the switching relay signals to the boiler there is a
      call for heat (in lieu of the thermostat in a single-zone system), the
      boiler responds to the call for heat and powers the attached primary pump
      (which is the system pump in a single-zone system described above).
      Therefore, the primary-side pump is powered directly off the boiler's
      control panel and doesn't need a connection on the switching relay.
      I hope this makes sense and that it helped.

      Answered on 4/15/2014 by Anonymous
    • A:

      Some people call the boiler loop the primary and some call it the secondary. I prefer to call it the primary because the heat originates from there. Why isn't the boiler turning on the primary pump? The relay just closes the dry TT contacts that turn on the boiler which turns on the primary pump. The switching relay turns on the secondary pumps when the thermostats call for heat. Be sure and connect the primary loop to the secondary loop thru closely spaced T's to hydrolicly separate the two loops. (Prevent pump interference in the two loops.) Primary and secondary looping is used with high resistant to flow boilers. High head boilers.

      Answered on 7/28/2014 by Homer from Nevada
    • A:

      On further re-consideration. Do this. Get a switching relay that covers all the pump zones+primary pump. Wire this way--connect all the thermostats and secondary pump to the switching relay. Connect the dry TT contacts to the thermostat connection of the primary pump zone. I assume you are not connecting the dry TT contacts to a boiler. If so forget this idea. The boiler has it's own transformer and the switching relay has it's own transformer. Connecting the two voltages together may put them in reverse polarity. Not good. When the thermostats call for heat the secondary pump and the primary pump will turn on together.

      Answered on 7/28/2014 by Homer from Nevada
    • A:

      To plainly answer your question, No! Can't be done. You need a single pump relay and a switching relay for the number of zones that you have. Connect the switching relay to the secondary pumps and the thermostats and the switching relay dry TT contacts to the primary single pump relay which will turn the primary pump on when the thermostats call for heat. Taco makes a pump that has a built in relay, I believe, eliminating the need for a single pump relay.

      Answered on 7/28/2014 by Homer from Nevada
  • 3 Zone Switching Relay

    Q:

    I've had this unit about 6 years, operating two zones in the house. Zone 2 works perfectly. Zone 1 functions correctly when the thermostat calls for heat but there is now an unusual "clicking" noise at the relay unit that continues even as the hot water circulates. There is no clicking heard when zone 2 operates. Both zones accurately heat to thermostat settings. What is wrong and how do I fix it?
    Asked on 1/17/2014 by Cloud

    3 answers

    • VERIFIED BUYER

      A:

      Sounds like relay chatter, which is likely one of two things:
      1. The relay is dying - the coil could be losing its mojo. Easiest way
      to investigate is to pull the cover off the unit. The relays are standard
      ice-cube units, you could swap 1 and 2, if the problem moves to 2 then it is
      the relay. You could also swap 1 with 3 (which it sounds like you are not
      using), if the problem goes away you're done. If you haven't worked with
      these relays, they just pull straight out of the base, then get pushed back
      in.
      2. The voltage to the relay coil is falling below the lower limit.
      Assuming you are using the built-in 24V supply and since zone 2 is working
      this would point to a bad connection or a bad thermostat switch. There
      could be just enough resistance that the voltage is right at the lower
      limit. If you are using a separate power supply then you would have to
      start there. Easiest way to test this is to disconnect the thermostat input
      for zone 1 and just connect a jumper directly at the controller. If the
      problem goes away then you know the problem is outside the box. If it
      doesn't go away (and your jumper connections are solid and clean) then the
      problem is inside the controller. See idea 1 above. If it is inside the
      unit you should be able to actually see the relays activate with the cover
      removed, if you see one cycling then you know the problem is with either
      that relay or the wiring to it.

      Answered on 1/17/2014 by DonS from Oakland, CA
    • VERIFIED BUYER

      A:

      Here is a guess:
      Does the red light for zone 1 blink when it clicks?
      1 If so, you might have a problem with the thermostat or the wire.
      Try swapping thermostats - top rule out a thermostat problem
      Try putting a jumper on the Zone 1 thermostat connection- to rule out a faulty wire
      2 If it does not blink you may have an internal problem with the relay - unusual, but possible.
      Try swapping the relay cubes for zone 1 with one of the others.
      Try moving the thermostat wire and the circulator wire to zone 3 if not is unused.
      Has any electrical work been done on or near the heating system?
      I have seen relays click and chatter when they get backfed voltage from another circuit
      This could happen on the low voltage or the line voltage side
      Are the thermostats the same?
      battery powered?

      Answered on 1/18/2014 by Anonymous
    • VERIFIED BUYER

      A:

      If both t-stats are powered by the same 24volt transformer, that rules out the transformer. If each t-stat has its own it's possible that that unit is intermittent, use a digital voltmeter to confirm if voltage is not constant. If voltage is steady, (24~28v). Relay is defective. If you have a spare zone move leads to that zone. Maybe relay can be replaced without replacing the entire unit. Bob.
      Sent from my iPad

      Answered on 1/18/2014 by Bob from Long Island
  • 1 Zone Switching Relay

    Q:

    I am getting ready to purchase radiant heat parts for my garage I would like to use a taco 3 speed pump ,tekmar 507 thermostate would this relay operate the pump?
    Asked on 10/17/2013 by needin help from Mars PA

    1 answer

    • CUSTOMER CARE

      A:

      Yes, this relay would interface the thermostat with the pump and the boiler when a call for heat is made.

      Answered on 10/18/2013 by PexSupply Staff from NY
Displaying questions 1-10Previous | Next »

Do you have a question about this product?